For golf club heads, reducing the thickness of a face portion having a ball striking surface has been a conventional pursuit (for example, reducing the thickness to 3.0 mm or less). A thinned face portion allows the face portion to flex with ease when a ball is struck. This leads to an effect of improving the coefficient of restitution, which in turn increases the travel distance of the ball.
The thinned face portion, however, commonly tends to make a loud sound when the ball is struck, which is resistant to attenuation. Such a tendency may adversely affect the feeling achieved by a golfer when striking a ball. As a way to attenuate such a sound, thus, a resin plate is provided on the back side of the face portion in a known technique.
Japanese Patent Laying-Open No. 2005-137634 describes a golf club head and a golf club in which a resin plate having a predetermined thickness is attached to a back surface of a ball striking portion of a face portion having a predetermined thickness. Japanese Patent Laying-Open No. 2005-137634 also describes that the provision of a groove portion in the resin plate allows the resin plate to easily follow the flexion of the face portion when a ball is struck, preventing or reducing peeling of the resin plate after repeated striking of the ball.